For everyone who uses LaTeX, just a heads up that MacTeX 2019 has been released: tug.org/mactex/newfeatures.html — the biggest change is that UTF8 is finally the default encoding!
I always prefer to use the minimal installer, which is only 76MB to download: tug.org/mactex/morepackages.html
Then I install the packages required as needed, here are the packages that make Pandoc work:
sudo tlmgr install lm-math lualatex-math luatexja abstract latexmk csquotes pagecolor relsize ucharcat mdframed needspace sectsty titling titlesec preprint layouts glossaries tabulary soul xargs todonotes mfirstuc xfor wallpaper datatool substr ctablestack ifetex adjustbox collectbox sttools wrapfig
To keep LaTeX up-to-date, you can run the command:
sudo tlmgr update --all
Or use the excellent GUI "TeX Live Utility (download it or automate the download using homebrew cask).